Our Kitten has become an important part of our family. When he came up missing we were very concerned that one of the neighborhood dogs had hurt him. We live in the country and our back yard joins the forest. Very often on a sunny day you would find our Kitten chasing through the leaves in search of "big game". When our Kitten was located some days later,He was in a tall tree and was unable to come down on his own.It would seem to be a crime to not allow kitten to play outside so we wanted to comeup with a compromise. My wife mention that it would be nice to have a radio tracker on the kitten's collar. She remember that in a college class we had built tracking transmitters and placed them on Land Turtles in order to track them to study their habits.The images below show the small radio beep beep transmitter that was built onto the Kittens collar. The weight and size are not a problem for Kitten . He has not show any resistance to it at all as it is only a one transistor circuit and has a range of one fourth to one half mile or about a Kilometer. The collar is powered by a small "N" cell .